It always amazes me how TALL that tower really is when I'm standing next to it, or even just seeing a picture like that. Even 111 Huntington (and obviously the pru) are SO tall when you take away the building in front of them. Just look at a picture of 111 and imagine the lines of the building continuing down to ground level.
What also amazes me is how tall other buildings are. I once drew with a ruler a comparison of large buildings. I made 1 inch = 100 meters, and I put the Pru and Hancock towers (along with Northeastern's West Village H) next to the Empire State Building and Dubai's Burj Dubai, and other such buildings. The HUGE Hancock tower is about a third the height of the Burj Dubai.